Grinder with movably supported frame

ABSTRACT

A system for use with a cutting wheel to capture and dispose of the dust discharged from such a wheel during operation. The term &#39;&#39;&#39;&#39;cutting wheel&#39;&#39;&#39;&#39; is used herein to mean any rotor including a belt or web traveling about one or more pulleys which, when brought into contact with a piece of work, will progressively remove particles of the work material, whether in a cut-off operation or in what is usually referred to as a grinding, abrading, shaping or polishing operation. The system is primarily intended for use with a relatively heavy wheel assembly which is supported, with its motive power, for limited, substantially universal movement relative to the work, and comprises a continuously-evacuated, elongated duct, a car defining a chamber continuously in communication with the interior of the duct as it moves along the length of the duct, an air scoop positioned in or near the stream of dust emanating from the wheel during operation and an articulated conduit providing communication and a driving connection between the scoop and the car.

' United States Patent Overmyer et al.

154] GRINDER WITH MOVABLY SUPPORTED FRAME [72] Inventors: Robert C.Overmyer, Indianapolis, Ind.; John R. Scheel, Ocqueoc, Mich.

[73] Assignee: Hawley Manufacturing Corporation,

Indianapolis, Ind.

[22] Filed: July 13, I971 [21] App]. No.: 162,240

[52] U.S. Cl ..5l/99, 51/273 [51 Int. CI. ..B24b 7/00, 1324b 9/00, 1324b55/06 [58] Field of Search ..417/313, 234; 51/99, 273; 98/115 VM, 86;144/252; 143/157 B [56] References Cited UNITED STATES PATENTS 1,966,9307/1934 Leander ..51/99 1,999,138 4/1935 Mason ..5l/273 2,923,227 2/1960Hawley ..98/86 3,478,668 11/1969 Scheel ..98/115 VM 3,498,004 3/1970Hensley ..5l/99 Oct. 17, 1972 [57] ABSTRACT A system for use with acutting wheel to capture and dispose of the dust discharged from such awheel during operation. The term cutting wheel" is used herein to meanany rotor including a belt or web traveling about one or more pulleyswhich, when brought into contact with a piece of work, willprogressively remove particles of the work material, whether in acut-off operation or in what is usually referred to as a grinding,abrading, shaping or polishing operation. The system is primarilyintended for use with a relatively heavy wheel assembly which issupported, with its motive power, for limited, substantially universalmovement relative to the work, and comprises a continuously-evacuated,elongated duct, a car defining a chamber continuously in communicationwith the interior of the duct as it moves along the length of the duct,an air scoop positioned in or near the stream of dust emanating from thewheel during operation and an articulated conduit providingcommunication and a driving connection between the scoop and the car.

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mCN A E PATENTEDncr 17 I972 3,59 137 SHEETBUFG INVENTORS BERT C.OVERMYER OH SCHEEL WMIJM ILd/M 4f ATTORN GRINDER WITH MOVABLY SUPPORTEDFRAME The present invention relates to the maintenance of a clearatmosphere in the vicinity of abrasive working tools and is particularlyconcerned with the provision of means moving witha heavy,mechanically-supported tool which is capable of limited, substantiallyuniversal movement relative to the work piece, to capture and dispose ofat least the dust, and in some cases the relatively heavy particlesremoved from the work, to prevent pollution of the immediateenvironment. A primary object of the invention, then, is to provide anapparatus, including an air scoop mounted to maintain a position in ornear the stream of dust emanating from such a tool, and to provide meanswhereby, at minimum cost and with minimum complication, that scoop maybe maintained always in communication with a source of vacuum whereby anair stream through the scoop will entrain the emissions from the tool tocarry them away to a point of disposal, thus preventing dispersion ofsuch emissions into the environmental atmosphere.

To that end, we have used a known means for maintaining a movable airreceptor in fluid communication with an evacuated duct, examples of suchmeans being disclosed in U.S. Pat. Nos. to Hawley 2,923,227 and Scheel3,478,668, and have provided novel means for establishing fluidcommunication and a driving connection between the above-mentioned scoopand such apparatus to accommodate the erratic gyrations of a tool of thecharacter here under consideration.

Further objects and advantages of the present invention will appear asthe description proceeds.

To the accomplishment of the above and related objects, our inventionmay be embodied in the forms illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that change may be made in the specificconstructions illustrated and described, so long as the scope of theappended claims is not violated.

In the drawings:

FIG. 1 is a plan view of a system constructed in accordance with thepresent invention and utilizing one commercial form of a tool known as aswing grinder;

FIG. 2 is a side elevation of the apparatus illustrated in FIG. 1;

FIG. 3 is a fragmentary plan of a modified form of the apparatusillustrated in FIG. 1;

FIG. 4 is a side elevation of the apparatus shown in FIG. 3;

FIG. 5 is a fragmentary plan of a system generally similar to that ofFIG. 3, except that the evacuated duct and associated car are of thecharacter illustrated in US. Pat. No. 3,478,668, rather than thatillustrated in US. Pat. No. 2,923,227;

FIG. 6 is a fragmentary elevation of the apparatus illustrated in FIG.5;

FIG. 7 is a fragmentary elevation of a system generally similar to thatillustrated in FIGS. 1 and 2, but showing a modified form of scoop andmounting therefor;

FIG. 8 is a plan view of the scoop of FIG. 7;

FIG. 9 is a somewhat diagrammatic, isometric view of a system generallysimilar to those illustrated above, but in which the tool is suspendedfrom a traveler, in turn suspended from an elevated platform supportingthe evacuated duct, and the articulated conduit means enters the ductcarried car at the side remote from the operator;

FIG. 10 is a fragmentary plan view of the system of FIG. 9;

FIG. 11 is a fragmentary, top plan view of a system constructed inaccordance with the present invention and applied to still heaviergrinding equipment of known characteristics; 7

FIG. 12 is an elevation of the apparatus illustrated in FIG. 11;

FIG. 13 is a view similar to FIG. 11 but showing the relation of theparts when the grinder wheel has been advanced toward the evacuatedduct;

FIG. 14 is an elevation of the system as illustrated in FIG. 13;

FIG. 15 is a fragmentary elevation, drawn to an enlarged scale, toillustrate details of boom operation and of conduit articulation;

FIG. 16 is an enlarged, fragmentary elevation of certain parts as viewedfrom the right of FIG. 15; and

FIG. 17 is a fragmentary elevation, partly in section, takensubstantially in the plane indicated by the line 17-17 of FIG. 15.

Referring more particularly to FIGS. 1 and 2, it will be seen that wehave illustrated, somewhat sketchily, one known form of swing grinder,indicated generally by the reference numeral 20. The grinder comprises acarriage 21 upon which is suitably journalled a cutting wheel 22. As hasbeen said, the term cutting wheel is used herein in a broad sense torefer to an abrasive device which, when brought into contact with a workpiece during operation, will remove particles of the work material,whether in a cut-off operation or in what is commonly referred to as agrinding or other comparable operation, A suitable guard 23 for thewheel is provided and a motor 24 is carried on the carriage 21 and issuitably connected to drive the wheel 22. This form of swing grinder isusually suspended from above. To that end, a ring 25 may be fixed to ablock or clamp 57 which, in turn, provides a journal mounting for ashaft 58 suitably fixed to the body of the carriage 21, whereby thecarriage may be oscillated, through arcs of approximately in eachdirection from its illustrated median position, about the axis of theshaft 58, without disturbing the block 57, the ring 25 or the hanger rod26 which provides a linking connection between the ring 25 and anoverhead ring 27. The ring 25, of course, is disposed in a vertical lineincluding the center of gravity of the loaded carriage 21 so that thecarriage will normally stand substantially in the horizontal positionillustrated in FIG. 2.

Handle bars 28 project rigidly from the rear end of the carriage 21whereby an operator may readily manipulate the carriage to swing itabout the axis of the shaft 58, about the axis of the link 26 to theopposite, alternative positions illustrated in broken lines in FIG. 1and forwardly and rearwardly about the axis of the ring 27 or about theaxis of the ring 25. Through these movements and various combinationsthereof, it will be apparent that the wheel 22 can be brought intocooperative engagement with the work 29 in a wide variety ofrelationships to perform varied operations upon the surface of thework.-

The structure as thus far described has long been commercially availableand is widely used; but in operation, it throws detached particles ofthe work material, and dust, in abroadcast fashion. Because theapparatus is so mobile, it has not been feasible effectively to catchand collect even the heavier particles, much less the dust emitted fromthe tool and the consequent pollution of the immediate environment hasbeen not only troublesome but, in many instances, actually dangerous tothe health of the workers.

According to the present invention, a continuouslyevacuated, elongatedduct 30 is arranged near the location of the grinder 20, one wall ofsaid duct being closed only by a flexible web 31. A car 32 is arrangedto travel along the length of the duct 30, said car defining a chamberand carrying equipment so cooperative with the web 31 that the chamberis always in open communication with the interior of the duct 30. Thedetails of construction through which this open communication ismaintained are fully disclosed in US. Pat. No. 2,923,227, aboveidentified.

An air scoop 33 is suitably supported from the carriage 21 with itsmouth positioned in substantial tangency to the wheel 22 so that saidscoop mouth is disposed within, or close'to, the stream of particles anddust emitted by the wheel during operation. The scoop mouth is arrangedso close to the origin of that stream and the velocity of the air streamentering the scoop mouth is so high that the particulate stream isconcentrated, and may even be bent, so that substantially all of theparticulate material is captured by the scoop.

Conduit means, indicated generally by the reference numeral 34, extendsbetween the scoop and the car 32 to maintain communication between themouth of the scoop and the interior of the chamber in the car 32; andthe conduit means is of such character as to establish a physicaldriving connection between the carriage 21 and the car 32 so that, nomatter what may be the complexity of the gyrations of the carriage 21,the car 32 will, as a consequence, move along the duct 30, under theinfluence of the articulated conduit means 34, to maintain thehigh-velocity air flow which entrains emissions from the wheel andcarries them into the duct 30, whence they are delivered, by suitablemeans (not shown) to a collection point.

The means and mode of articulation of the conduit means 34 are animportant feature of the present invention. Thus, in the form ofinvention illustrated in FIGS. 1 and 2, the conduit means comprises afirst section 35 perpendicularly fixed to and penetrating one wall ofthe car 32 to enter the chamber therewithin. A second section 36 is anelbow and is joined to the section 35 through a swivel connection 37 ona vertical axis. A third section 38 is joined to the section 36 througha swivel connection 39 on a substantially horizontal axis and, in turn,is connected to a fourth elbow section 40 through a swivel connection 41on a horizontal axis perpendicular to the axis of the swivel connection39. A fifth elbow section 42 is connected to the section 40 through ahorizontal swivel connection 43 on a horizontal axis substantiallyparallel to the axis of the connection 39 and a sixth section 44 isconnected to the section 42 through a swivel connection 45 on a subblock57 to the conduit section 44 to immobilize that section relative to theblock so that, when the operator, for instance, bears down on theright-hand handle bar and lifts on the left-hand handle bar 28 as viewedin FIG. 1, the carriage 21 and the scoop 23 will turn in a clockwisedirection as viewed from the left, the conduit section 44 will standstill and the swivel connection 46 will permit turning movement of thescoop 33 with the carriage 21.

It will be readily perceived that, if the carriage 21 is moved towardthe right as viewed in FIG. 1, the acute angular relationship of theconduit section 38 with the length of the duct 30 will cause the car 32to move upwardly along the duct, as seen in FIG. 1, while the angleincluded between the conduit section 38 and the length of the duct willbe decreased, various of the swivel connections coming into actionduring that movement. Equivalently, if the carriage 21 is moved awayfrom the duct, the car 32 will be caused to move downwardly along thatduct, as viewed in FIG. 1 and the angle included between the conduitsection 38 and the length of the duct will be enlarged.

Similarly, if the carriage 21 is turned about the axis of the hanger 26in a clockwise direction toward the lower shadow position of FIG. 1, itis obvious that both components of the path of the axis of the swivelconnection 45 will tend to move the car 32 downwardly along the duct 30,as viewed in FIG. 1.

In the form of invention illustrated in FIGS. 3 and 4, it will beapparent that the carriage 21 and its directly associated parts, and theduct 30 and car 32 and conduit section 35 will be the same as in theform illustrated in FIGS. 1 and 2. In this installation, however, thesecond section 48, swivel connection 49, third section 50 and swivelconnection 51 are somewhat differently arranged and the fourth section52 is reversed relative to the section 38. With its straight endassociated with the section 50 through the swivel connection 53, theremote end of the section 52 is turned downwardly and connected to afifth section 54 through a swivel connection 55. The other end of thesection 54 communicates with the scoop 33 through a swivel connection 56equivalent to the connection 46 of FIG. 2; and the section 54 isimmobilized relative to the block 57 by means of the brace 47. Theoperation of this form of the invention is in all respects similar tothat described in connection with FIGS. 1 and 2.

In the arrangement illustrated in FIGS. 5 and 6, the flexible web isarranged to guard an opening in a side, vertical wall of the duct 61 andthe car 62 must therefore ride in association with that side wall,rather than the top wall, of the duct. The details of such anassociation are fully disclosed in the above-identified United Statespatent 3,478,668; but it may be briefly stated that the car is equippedwith pair of canted wheels 63 which bear against the inner surface of anupstanding rail 64 on the duct, and with a pair of horizontal wheels 69which bear against the outer surface of a depending rail 65 on the duct.In this instance, a fitting 66 is fixedly secured in perpendicularrelation to the lower wall of the car 62 and communicates with thechamber therein and a section 68 of the conduit means, equivalent to thesection 50 of FIG. 3, connects the section 68 with the section 52through swivel connections 51 and 53. i

In all essential respects, the system of FIGS. 5 and 6 performs in themode of the system of FIGS. 3 and 4.

The form of invention illustrated in FIGS. 7 and 8 embodies a differentform of scoop 71. As illustrated, the scoop 71 may be of rectangularcross section and may consist of a mouth section 72 of relatively smalleffective area, and a plurality of sections 73, 74 and 75 ofprogressively increasing effective cross sectional capacity. It will beapparent that, with a given degree of evacuation of the duct 30, thisscoop construction will provide increased velocity of the air streamentering the scoop mouth.

FIG. 7 also illustrates a particular means 76 for securing the scoop 71to the carriage 21 to move therewith relative to the block 57.

FIGS. 9 and illustrate a different commercial form of carriage 81, adifferent mode of suspension of the swing grinder and a different butanalogous conduit means providing a fluid connection and a drivingconnection betweenthe scoop and the car providing fluid communicationwith the interior of the evacuated duct. In this assembly, the carriage81 is suspended by .the link 26 from a traveler 82 mounted to move alonga monorail 83 suspended from a bracket or shelf 84 which carries theduct 85 which is the functional equivalent of the duct 30. This, ofcourse, confers even greater mobility upon the carriage 81.

The car 86 is the equivalent of the car 32 except that the first conduitsection 87 is secured to and penetrates that .side wall of the car whichis remote from the operators station. A second section 88 communicateswith the section 87 through a swivel connection 89 on a vertical axisand a third section 90, generally similar to the section 38 communicateswith the section 88 through a swivel connection 91 on a horizontal axis.A fourth section 92 is an elbow connected to the section 90 through aswivel connection 93 on a horizontal axis perpendicular to the axis ofthe connection 91 and a fifth section 94 is connected to the section 92through a swivel connection 95 on an axis parallel with the axis of theconnection 91. A sixth section 96 communicates withthe section 94through a vertical swivel connection 97 and connects with a verticalsection 99 of the scoop 100 through a swivel connection 98 on ahorizontal axis.

In this illustration, we have suggested a conveyor 101 paralleling thepath of the duct 85 to convey work pieces 102 successively past thegrinding station. The conveyor parallels, also, the monorail 83 so that,if necessary or desirable, a particular work piece on the conveyor 101may be followed for a significant period of time as the operator pushesthe swing grinder along the path of the conveyor, causing the traveler82 to move along the monorail 83.

In shadow outline in FIG. 9, we have suggested that, if desired, theduct 85 and car 86 may be supported on the floor, rather than on anoverhead bracket system, in which case the first section 87 of theconduit means will extend upwardly, rather than downwardly, from thecar.

In FIGSv 11 to 17, we have illustrated the applicability of our exhaustsystem to an even heavier type of grinder installation. A firstautomotive wheeled vehicle 110 is supported to travel on rails ortrackway 1 1 1. The vehicle 110, in turn, supports rails or trackway 112arranged in perpendicular relation to the trackway 111; and a secondautomotive wheeled vehicle 113 is supported to travel on the trackway112. This arrangement, of course, provides for limited universalmovement of the vehicle 113 in a single plane.

A boom 114 is supported from the vehicle 113 for vertical oscillationabout the axis 115. Near its distal end, the boom 114 carries a spindle116 from which is suspended, for oscillation about the axis of thespindle, a hanger 117 carrying a cutting wheel 118. A fluid motor 119isconnected between the boom 114 and a fixed point on the vehicle 113 toeffect the above-mentioned oscillation of the boom. It will be perceivedthat this construction provides for limited movement of the wheel 118relative to the vehicle 113 about separate axes. Thereby, limiteduniversal movement of the wheel relative to the work table 121 and work122 supported thereon is achieved so that a skillful operator in the cabcan manipulate the heavy wheel 118 to accomplish any desired shaping ofthe work 122.

Customarily a bin 123 parallels the trackway 111 in i such a positionthat the heavier particles of material emitted from the wheel 118hopefully will be deposited and collected therein. The structure ofFIGS. 11 to 17 thus far described is commercially known.

A continuously-evacuated duct 124 may conveniently be supported upon theroof of the bin 123 to parallel the trackway 11 1, and a car 125defining an interior chamber is mounted to travel along the said ductwith the chamber always in open communication with the interior of theduct 124 as explained in the discussion of FIG. 1. A scoop 131 issuitably fixed to the boom 114 with its mouth arranged in substantialtangency with the wheel 118 to capture emissions from the wheel, asexplained above. Conduit means maintaining open communication betweenthe scoop and the interior of the car 125 and providing, also, a drivingconnec tion between the boom 114 and said car, may comprise a firstsection 126 perpendicularly fixed to, and opening through, a wall of thesaid car. A second section 127 may be S-shaped, as shown, and isconnected to the section 126 through a swivel connection 128 upon avertical axis, and to a further section indicated generally by thereference numeral 129 through a swivel connection 130 likewise on avertical axis. The section 129, in turn, communicates with the scoop 131through a swivel connection 138 on a horizontal axis.

Depending upon the particular configuration of the commercial grindingassembly, the section 129 may take various forms. In the illustratedembodiment of our invention, as is most clearly to be seen in FIG. 16,the section 129 consists of an elbow 132 supported from the vehicle 113by a clamp ring 133 and rigid brace means 134. An L-shaped section 135is connected to the elbow 132 through a swivel connection 136 on ahorizontal axis, and another L-shaped section 137 has its longer legtelescopically received in the longer, vertical leg of the section 135,while its shorter leg is connected to the scoop 131 through a swivelconnection 138 having a horizontal axis and disposed in a common planewith the connection 136.

It will be perceived that the performance of the apparatus disclosed inFIGS. 11 to 17 is directly analogous to that described in the discussionof FIGS. 1 to 10. As the wheel 118 is maneuvered by manipulation of theseveral controls, the relationship of the scoop 131 to the wheel remainsconstant to entrain emissions from the wheel and to conduct them to theduct 124 for suitable disposition. In these heavier machines, it maysometimes be advisable to permit the heavier particles to be dischargedto the bin 123, the scoop 131 being so disposed as to entrain onlyrelatively light dust; and of course that can be done by so selectingthe position of the scoop relative to the wheel, and the volume andvelocity of the air stream flowing into the scoop mouth that suchheavier particles, following a lower trajectory, will escapeentrainment. Any such selective entrainment, of course, will depend to alarge extend upon the relation between the advantages of substantiallycomplete entrapment of the emissions from the wheel and thedisadvantages arising from attrition upon the interior of the conduitmeans by the heavier particles and the capacity of the air streameffectively to move extremely heavy particles through the tortuous pathof the conduit means.

What is claimed is:

1. In combination, a carriage supported for substantially universalmovement in a plurality of directions and about a plurality of axes, acutting wheel mounted for rotation about an axis carried on saidcarriage, means on said carriage for driving said wheel, a stationary,elongated, continuously-evacuated duct, a car mounted for travel alongsaid duct and defining a chamber continuously in communication with theinterior of said duct, a scoop having an open mouth disposed generallytangentially adjacent the periphery of said wheel to receive dustdischarged from said wheel, and self-sustaining conduit meansestablishing communication between said scoop and the interior of saidchamber and establishing a driving connection between said carriage andsaid car, said conduit means including a plurality of swivel connectionson different axes to accommodate such substantially universal movementof said carriage.

2. The combination of claim 1 in which said carriage is suspended froman overhead point by linking means attached to said carriage at a pointvertically aligned with the center of gravity of said carriage and itsload.

3, The combination of claim 2 in which said linkage means is a rigid barand the attachment of said bar to said carriage includes a freering-and-hook means.

4. The combination of claim 2 in which said conduit means includes afirst section substantially perpendicular to and rigidly fixed to a wallof said car, a second section swivelly connected to said first sectionupon a first substantially vertical axis, a third section swivellyconnected to said second section upon a first substantially horizontalaxis, a fourth section swivelly connected to said third section upon asecond substantially horizontal axis substantially perpendicular to saidfirst horizontal axis, a fifth section swivelly connected to said fourthsection upon a third substantially horizontal axis substantiallyparallel with said first horizontal axis, and a sixth section swivellyconnected to said fifth section upon a second substantially verticalaxis, said sixth section further being swivelly connected to said scoopupon a fourth substantially horizontal axis, said second horizontal axisbeing disposed at a variable acute angle to the line of travel of saidcar.

5. The combination of claim 2 in which said conduit means includes afirst end section rigidly fixed to a wall of said car and communicatingwith the interior thereof, a second end section swivelly connected tosaid scoop, at least one intermediate section having swivel connectionsupon relatively perpendicular axes at its opposite ends, and a pluralityof further sections swivelly connected in said conduit means to completea communication connection between said scoop and the interior of saidcar and a driving connection between said carriage and said car, saidone intermediate section being disposed at a variable acute angle to theline of travel of said car.

6. The combination of claim 2 in which said conduit means includes afirst section substantially perpendicular to and rigidly fixed to a wallof said car, a second section swivelly connected to said first sectionupon a first substantially vertical axis, a third section swivellyconnected to said second section upon a first substantially horizontalaxis, a fourth section swivelly connected to said third section upon asecond substantially horizontal axis substantially perpendicular to saidfirst horizontal axis, a fifth section swivelly connected to said fourthsection upon a second substantially vertical axis and swivelly connectedto said scoop upon a third substantially horizontal axis, said firsthorizontal axis being disposed at a variable acute angle to the line oftravel of said car. i

7. The combination of claim 1 in which said carriage comprises a firstwheeled vehicle reciprocable upon a first trackway, a second trackway onsaid first vehicle and arranged transversely relative to said firsttrackway, a second wheeled vehicle reciprocable upon said secondtrackway, and a boom mounted on said second vehicle to rock about anaxis transverse relative to said second trackway, means on said firstvehicle for driving said first vehicle reversely along said firsttrackway, means for driving said second vehicle reversely along saidsecond trackway, and power means for rocking said boom, said cuttingwheel being mounted on said boom.

8. The combination of claim 7 in which said conduit means comprises afirst section substantially perpendicular to and rigidly fixed to a wallof said car, a second section swivelly connected to said first sectionupon a first substantially vertical axis, and a third section swivellyconnected to said second section upon a second substantially verticalaxis, said third section further being connected to said scoop, and saidthird section further being extensible and contractable in length.

9. The combination of claim 8 in which one of said trackways issubstantially parallel with said duct.

10. The combination of claim 9 in which a line joining said verticalaxes is disposed at a variable acute angle to the line of travel of saidcar.

g gi UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,698,l37 Dated October 17, 1972 lnventofls) Robert C. Overmyer and JohnR. Scheel It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 4 line 21, "that" should be the line 57, after "with" and before"pair" insert a Column 7, line 13, "extend" should be extent line 45(Claim 3 line 1) "linkage" should be linking Signed and sealed this 2+th day of April 1973.

(SEAL) fittest:

EDWARDd I. FLETCHER, JR. RGBERT GOTTSCHALK Attesting OfficerCommissioner of Patents

1. In combination, a carriage supported for substantially universalmovement in a plurality of directions and about a plurality of axes, acutting wheel mounted for rotation about an axis carried on saidcarriage, means on said carriage for driving said wheel, a stationary,elongated, continuously-evacuated duct, a car mounted for travel alongsaid duct and defining a chamber continuously in communication with theinterior of said duct, a scoop having an open mouth disposed generallytangentially adjacent the periphery of said wheel to receive dustdischarged from said wheel, and self-sustaining conduit meansestablishing communication between said scoop and the interior of saidchamber and establishing a driving connection between said carriage andsaid car, said conduit means including a plurality of swivel connectionson different axes to accommodate such substantially universal movementof said carriage.
 2. The combination of claim 1 in which said carriageis suspended from an overhead point by linking means attached to saidcarriage at a point vertically aligned With the center of gravity ofsaid carriage and its load.
 3. The combination of claim 2 in which saidlinkage means is a rigid bar and the attachment of said bar to saidcarriage includes a free ring-and-hook means.
 4. The combination ofclaim 2 in which said conduit means includes a first sectionsubstantially perpendicular to and rigidly fixed to a wall of said car,a second section swivelly connected to said first section upon a firstsubstantially vertical axis, a third section swivelly connected to saidsecond section upon a first substantially horizontal axis, a fourthsection swivelly connected to said third section upon a secondsubstantially horizontal axis substantially perpendicular to said firsthorizontal axis, a fifth section swivelly connected to said fourthsection upon a third substantially horizontal axis substantiallyparallel with said first horizontal axis, and a sixth section swivellyconnected to said fifth section upon a second substantially verticalaxis, said sixth section further being swivelly connected to said scoopupon a fourth substantially horizontal axis, said second horizontal axisbeing disposed at a variable acute angle to the line of travel of saidcar.
 5. The combination of claim 2 in which said conduit means includesa first end section rigidly fixed to a wall of said car andcommunicating with the interior thereof, a second end section swivellyconnected to said scoop, at least one intermediate section having swivelconnections upon relatively perpendicular axes at its opposite ends, anda plurality of further sections swivelly connected in said conduit meansto complete a communication connection between said scoop and theinterior of said car and a driving connection between said carriage andsaid car, said one intermediate section being disposed at a variableacute angle to the line of travel of said car.
 6. The combination ofclaim 2 in which said conduit means includes a first sectionsubstantially perpendicular to and rigidly fixed to a wall of said car,a second section swivelly connected to said first section upon a firstsubstantially vertical axis, a third section swivelly connected to saidsecond section upon a first substantially horizontal axis, a fourthsection swivelly connected to said third section upon a secondsubstantially horizontal axis substantially perpendicular to said firsthorizontal axis, a fifth section swivelly connected to said fourthsection upon a second substantially vertical axis and swivelly connectedto said scoop upon a third substantially horizontal axis, said firsthorizontal axis being disposed at a variable acute angle to the line oftravel of said car.
 7. The combination of claim 1 in which said carriagecomprises a first wheeled vehicle reciprocable upon a first trackway, asecond trackway on said first vehicle and arranged transversely relativeto said first trackway, a second wheeled vehicle reciprocable upon saidsecond trackway, and a boom mounted on said second vehicle to rock aboutan axis transverse relative to said second trackway, means on said firstvehicle for driving said first vehicle reversely along said firsttrackway, means for driving said second vehicle reversely along saidsecond trackway, and power means for rocking said boom, said cuttingwheel being mounted on said boom.
 8. The combination of claim 7 in whichsaid conduit means comprises a first section substantially perpendicularto and rigidly fixed to a wall of said car, a second section swivellyconnected to said first section upon a first substantially verticalaxis, and a third section swivelly connected to said second section upona second substantially vertical axis, said third section further beingconnected to said scoop, and said third section further being extensibleand contractable in length.
 9. The combination of claim 8 in which oneof said trackways is substantially parallel with said duct.
 10. Thecombination of claim 9 in which a line joining said vertical axes isdisposed at A variable acute angle to the line of travel of said car.